It is desirable to introduce fresh, outside air into a vehicle and exhaust the stale, inside air. This is particularly true if smoking occurs in the vehicle. The ventilator used for accomplishing this must be inexpensive and simple in construction, and allow for precise control over the flow of air. It is desirable that the ventilator be capable of use in all weather conditions without subjecting the occupants of the vehicle to wind noise or adverse exterior weather such as rain. It should not be a requirement that the vehicle be altered by the use of screws or other mechanical fasteners.